// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2008-2015 Gael Guennebaud <gael.guennebaud@inria.fr>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#ifndef EIGEN_SPARSE_CWISE_UNARY_OP_H
#define EIGEN_SPARSE_CWISE_UNARY_OP_H

namespace Eigen {

namespace internal {

template<typename UnaryOp, typename ArgType>
struct unary_evaluator<CwiseUnaryOp<UnaryOp, ArgType>, IteratorBased>
	: public evaluator_base<CwiseUnaryOp<UnaryOp, ArgType>>
{
  public:
	typedef CwiseUnaryOp<UnaryOp, ArgType> XprType;

	class InnerIterator;

	enum
	{
		CoeffReadCost = int(evaluator<ArgType>::CoeffReadCost) + int(functor_traits<UnaryOp>::Cost),
		Flags = XprType::Flags
	};

	explicit unary_evaluator(const XprType& op)
		: m_functor(op.functor())
		, m_argImpl(op.nestedExpression())
	{
		EIGEN_INTERNAL_CHECK_COST_VALUE(functor_traits<UnaryOp>::Cost);
		EIGEN_INTERNAL_CHECK_COST_VALUE(CoeffReadCost);
	}

	inline Index nonZerosEstimate() const { return m_argImpl.nonZerosEstimate(); }

  protected:
	typedef typename evaluator<ArgType>::InnerIterator EvalIterator;

	const UnaryOp m_functor;
	evaluator<ArgType> m_argImpl;
};

template<typename UnaryOp, typename ArgType>
class unary_evaluator<CwiseUnaryOp<UnaryOp, ArgType>, IteratorBased>::InnerIterator
	: public unary_evaluator<CwiseUnaryOp<UnaryOp, ArgType>, IteratorBased>::EvalIterator
{
  protected:
	typedef typename XprType::Scalar Scalar;
	typedef typename unary_evaluator<CwiseUnaryOp<UnaryOp, ArgType>, IteratorBased>::EvalIterator Base;

  public:
	EIGEN_STRONG_INLINE InnerIterator(const unary_evaluator& unaryOp, Index outer)
		: Base(unaryOp.m_argImpl, outer)
		, m_functor(unaryOp.m_functor)
	{
	}

	EIGEN_STRONG_INLINE InnerIterator& operator++()
	{
		Base::operator++();
		return *this;
	}

	EIGEN_STRONG_INLINE Scalar value() const { return m_functor(Base::value()); }

  protected:
	const UnaryOp m_functor;

  private:
	Scalar& valueRef();
};

template<typename ViewOp, typename ArgType>
struct unary_evaluator<CwiseUnaryView<ViewOp, ArgType>, IteratorBased>
	: public evaluator_base<CwiseUnaryView<ViewOp, ArgType>>
{
  public:
	typedef CwiseUnaryView<ViewOp, ArgType> XprType;

	class InnerIterator;

	enum
	{
		CoeffReadCost = int(evaluator<ArgType>::CoeffReadCost) + int(functor_traits<ViewOp>::Cost),
		Flags = XprType::Flags
	};

	explicit unary_evaluator(const XprType& op)
		: m_functor(op.functor())
		, m_argImpl(op.nestedExpression())
	{
		EIGEN_INTERNAL_CHECK_COST_VALUE(functor_traits<ViewOp>::Cost);
		EIGEN_INTERNAL_CHECK_COST_VALUE(CoeffReadCost);
	}

  protected:
	typedef typename evaluator<ArgType>::InnerIterator EvalIterator;

	const ViewOp m_functor;
	evaluator<ArgType> m_argImpl;
};

template<typename ViewOp, typename ArgType>
class unary_evaluator<CwiseUnaryView<ViewOp, ArgType>, IteratorBased>::InnerIterator
	: public unary_evaluator<CwiseUnaryView<ViewOp, ArgType>, IteratorBased>::EvalIterator
{
  protected:
	typedef typename XprType::Scalar Scalar;
	typedef typename unary_evaluator<CwiseUnaryView<ViewOp, ArgType>, IteratorBased>::EvalIterator Base;

  public:
	EIGEN_STRONG_INLINE InnerIterator(const unary_evaluator& unaryOp, Index outer)
		: Base(unaryOp.m_argImpl, outer)
		, m_functor(unaryOp.m_functor)
	{
	}

	EIGEN_STRONG_INLINE InnerIterator& operator++()
	{
		Base::operator++();
		return *this;
	}

	EIGEN_STRONG_INLINE Scalar value() const { return m_functor(Base::value()); }
	EIGEN_STRONG_INLINE Scalar& valueRef() { return m_functor(Base::valueRef()); }

  protected:
	const ViewOp m_functor;
};

} // end namespace internal

template<typename Derived>
EIGEN_STRONG_INLINE Derived&
SparseMatrixBase<Derived>::operator*=(const Scalar& other)
{
	typedef typename internal::evaluator<Derived>::InnerIterator EvalIterator;
	internal::evaluator<Derived> thisEval(derived());
	for (Index j = 0; j < outerSize(); ++j)
		for (EvalIterator i(thisEval, j); i; ++i)
			i.valueRef() *= other;
	return derived();
}

template<typename Derived>
EIGEN_STRONG_INLINE Derived&
SparseMatrixBase<Derived>::operator/=(const Scalar& other)
{
	typedef typename internal::evaluator<Derived>::InnerIterator EvalIterator;
	internal::evaluator<Derived> thisEval(derived());
	for (Index j = 0; j < outerSize(); ++j)
		for (EvalIterator i(thisEval, j); i; ++i)
			i.valueRef() /= other;
	return derived();
}

} // end namespace Eigen

#endif // EIGEN_SPARSE_CWISE_UNARY_OP_H
